Not having a smartphone or access to a high-speed mobile network doesn’t mean you don’t still want your phone to act brainy and speedy. That’s the premise behind Australian startup biNu, whose free Java app can be downloaded onto most basic phones and used over 2G wireless networks—which remain common in many developing countries—to update Facebook and Twitter, read news, search the Web, and more.

You could use a mobile browser to do the same thing, but biNu cofounder Gour Lentell says biNu’s software is much faster and more data-efficient because it shifts most of the data processing away from the phone and onto distant servers.

Most of the phones in use around the world today are still basic “dumb” phones. According to an estimate from IT and research consulting company Gartner, about 25 percent of the 4.3 billion phones in use worldwide are smartphones. This year, Gartner expects sales of more than 1.85 billion phones, about 45 percent of which will be smartphones.

For the time being, then, biNu has plenty of potential users. Since launching 18 months ago, it has snagged four million customers. Most are in Asia and Africa—top countries include India, Bangladesh, Nigeria, Ethiopia, and Zimbabwe. While they don’t pay to use biNu itself, they pay for the data consumed by using it (Lentell says users are on prepaid phone plans).

Surfing the Web on a laptop or desktop computer using a broadband connection is relatively painless: a browser does the work necessary to properly render the incoming HTML and other data on our screen. Using a mobile browser on a smartphone offers a similar experience, though generally with slower connection speeds and simpler, mobile-geared web pages. But trying to look at a website on a feature phone—even if it’s a simple WAP site—can be much more tedious, since these devices have very limited processing capacities. And if you’re trying to do this over a 2G network, it’s even worse.

BiNu takes a different approach. When you peruse an app through the main biNu app, each word you see on your screen was previously broken down, letter by letter, into a tiny image file on a remote server and sent wirelessly to your phone along with instructions about where it should go on the screen, Lentell says. Once they’ve been sent, letters can essentially be recycled on subsequent screens of text, he says, and biNu also supports regular images. In addition, biNu precaches lots of text, such as news articles in its news reader app, so pages load quickly when you click on a headline on your screen.

There are limitations: you can’t, for example, watch videos through biNu’s YouTube app, or play most games. However, Lentell says biNu is 10 times faster than using a standard browser on a feature phone, and it requires 10 times less data.”Since we’re so efficient on data, the cost to the end user is relatively small compared to starting the browser and doing the same thing,” he says.

Still, Brian Blau, a Gartner analyst, wonders how useful biNu will be as smartphones become more and more prevalent around the world. He’s also concerned that it could be hampered by rules that social networks like Twitter and Facebook may make about how third-party companies present content that’s created on their networks. “You kind of have to wonder about the longevity of something like this,” he says. “But for today I think it’s a relatively interesting solution.”